Torque-transmitting mechanisms, such as fluid-operated friction clutches, employ a rotating shaft and a rotatable housing, which are interconnected by a plurality of friction discs. The friction discs are generally referred to as a clutch pack and are brought into frictional engagement by a fluid-operated piston and are reacted against a reaction or backing plate, which is generally connected with the rotating shaft.
The backing plate is retained on the shaft by a locking ring, such as either a spiral type locking ring or a C-type locking ring. The locking ring is subjected to centrifugal forces during rotation of the torque-transmitting mechanism and is especially critical to such rotating forces when the torque-transmitting mechanism is disengaged. The use of a locking ring can result in high load applications at the locking ring and spline interface, which reduces the backing plate section size at this loading area. Uneven loading can also occur from the retaining ring gap when a snap ring or C-ring is employed. The retaining ring or locking ring also requires that small fillet radii be present in the groove on the shaft on which the locking ring is positioned.